Duncan symington



(No Model.) D. SYMINGTON.

STEAM ENGINE GOVERNOR.

Patented A r. 24, 1894.

Witn/eses "erably the engine shaft.

UNITED STATES.

PATENT OFFICE.

DUNCAN SYMINGTON, on berRorr, MICI1IGAN,ASSIGNOR or ONE-HALF TO THE FRONTIER IRON woRKs, OF SAME PLACE.

STEAM-ENGINE GOVERNOR.

SPECIFICATION forming part of Letters Patent No. 518,728, dated April 24, 1894. Application filed December 19, 1891. Serial No. 415,581. (No model.)

the disk or wheel upon the engine shaft carries ashifting eccentric to control the cut-ofi of the valve.

The invention consists in the peculiar con-- struction of the governor whereby a single spring is acted on at opposite ends by the.

governor weights, and further in the peculiar construction of a counterbalance for the eccentric and the parts attached thereto, and further in the peculiar construction, arrange ment and combination of the various parts, all as more fully hereinafter described.

In the drawings, Figure 1 is an elevation of my improved governor. Fig. 2 is a similar elevation showing the parts in the position in which the eccentric is moved to its outermost position. Fig. 3 is a vertical, central section on line a: m Fig. 1, and Fig. 4: shows in detached perspective the eccentric and the counter balance weight.

A is a shaft driven by the engine and pref- B is a disk or wheel secured thereto forming the support for the governor.

O and D are the governor weights arranged at opposite sides of the disk B. These weights are formed at the outer ends of the arms E and F respectively, which are pivoted to the disk B upon opposite sides. The weight D is connected with the eccentric G by means of the connecting link H, and theweight O is connected with the arm I of the eccentric by means of the extension J of the arm Eand connecting link K and the curved extension L of the arm I. The arm I is pivoted on a pin M to one side of the disk, and the eccentric is free to vibrate on that pivotin shifting from a concentric to a more or less eccentric position in relation to the shaft.

N is the eccentric strap, and O is the connecting rod to the valve.

a. is a coil spring sleeved upon the rod I) which at one end pivotally connects with the arm F and at the other end is provided with a cross-head 0 upon which the spring rests.

f are rods connecting the cross-heads g and passing through the cross-head c, the whole forming two arms bearing upon opposite ends of the spring. The lower cross-head g. is connected to the rod h which in turn connects to the lever t, having the links j at its outer end which connects it to the weight 0.

In Fig. 1 the parts are shown with the eccentric in substantially a concentric relation to the shaft, or in its extreme inward position in which position it would not move the valve and in Fig. 2 the parts are shown with the weights extended and the eccentric at the limit of its adjustment in which position the valve is shown to its greatest extent. It will be seen that in the outward movement of the weights due to the centrifugal action, the spring a will be compressed between the'crossheads 0 and g. Theelfect of this is that exactly the same tension is brought upon the two weights for they act against each other upon the same spring, thus overcoming thedifficulty which arises in the use of two springs for obtaining the same tension for both weights.

In the use of governors, Iemploy what I call a pendulous eccentric, that is, an eccentric suspendedfrom an arm, such as I. It is evident that when said arm I is in the horizontal position as shown in Fig. 2, or when it is in anyother position, except its vertical position, the weight of the eccentric and the connecting parts will act against the governor weights and cause a variation in the movement of the valve. To overcome this and to counterbalance the eccentric in all positions,

I employ a counterbalance weight Z, apertured to embrace the shaft and havingamovement about the same corresponding to the shifting movement of the eccentric. This weight is pivotally connected with the disk by means of the pin m upon the under side of the lever or extension at on one side thereof, and at the balance the same, thus the weight of the eccentric and its connecting parts are counterbalanced at all times allowing the governor to perfectly control the shifting of the eccentric.

This governor is intended to operate an auxiliary valve, preferably one within the main valve which cuts off, say at a quarter. When the engine is run at its normal speed the parts are in the position shown in Fig. 1 and the auxiliary valve stands stationary with its ports opposite the ports in the steam chest, and the main valve travels and cuts off without being effected by the auxiliary valve. As soon as the speed of the engine increases beyond the normal there is a travel of the auxiliary valve in relation to the main valve, throttling the same proportionate to the increase inspeed, so that the greater the throw of the eccentric the greater the cut off of the auxiliary valve in relation to the main valve.

What I claim is 1. In a governor for engines, the combination of the shaft, the shifting eccentric and the governor therefor, of counterbalance weights for the eccentric pivoted to the disk and acting through a lever to oppose the weight of the eccentric, a sliding connection between the weights and a spring at the connection substantially as described.

2. In a governor for steam engines, the combination with the drive shaft, the disk thereon, an eccentric having an arm pivoted at its outer end to one side of the disk, suitable governing devices for the eccentric, of a counterbalance weight pivotally suspended from the disk and a lever on said weight engaged with the eccentric whereby the eccentric is counterbalanced, substantially as described.

In testimony whereof I affix my signature in presence of two Witnesses.

DUN CAN SYMINGTON.

Witnesses:

N. L. LINDOP, M. B. ODOGHERTY. 

